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Are you ready for your cattle joining this year? 

With the end of the current calving season getting closer, producers should be preparing for the upcoming joining season.

We thought a quick check list for producers would be helpful and vet Andrew Denman put together a few things to think of sooner rather than later....

1. Pre joining check of bulls: OVH can do a range of testing including general physical examinations, semen testing and service ability testing.

2. Vaccinations: Vibrio for Bulls and Pestivirus, 7in1 etc for Bulls/Cows/Heifers

3. Joining length and ratio: Every enterprise is run differently but you should think about why you do what you do. How long do you join for? How many cows per bull? Multi sire vs single sire joining? Do you rotate your bulls? Do you have back up bulls available?

4. Heifer management: Make sure your heifers make their breed specific joining weight. Also at OVH we recommend joining the heifers two weeks before the mature cows to give them an increased chance to get back in calf next year.

If you have any questions about joining management then feel free to talk to any of the vets at OVH.

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Contents of this newsletter

01  The importance of semen morphology

02  What is laminitis?

03  Your guide to cattle castration

04  The dreaded dummy foal

05  Managing coccidiosis in stock

06  Good grazing practices for environmental management

01 The importance of semen morphology
Angus bull cut

In recent years, we have been testing more and more bulls' semen morphology. This basically involves looking at the shape of sperm, to find anomalies which are associated with poor fertility. Here’s some of the technicalities:

1. The 70% Rule

There has long been the belief that there is a threshold of observable sperm morphological abnormalities above which fertility became compromised. This threshold has been remarkably consistent at approximately 30%. In bulls, this was validated in a series of natural mating trials in Texas where bulls pre-selected for good sperm morphology (70% or greater normal sperm) achieved significantly more pregnancies than unselected bulls. More recently, work in a variety of areas such as IVF and studies on sperm DNA damage have come to a similar conclusion. 

Although the mechanisms behind this relationship are not immediately apparent, one possibility is that damaged sperm produce deleterious materials (e.g. reactive oxygen species) which adversely affect the entire sperm population. 

2. Compensable vs Uncompensable Sperm Defects

Within the 70% rule, further analysis is possible. Abnormalities categorised as compensableare those whose deficiencies can be compensated for by increasing the number of sperm in the ejaculate. In general, compensable defects are those which prevent the affected sperm from reaching the fertilisation site. They include problems associated with motility (ability to swim).

Uncompensable abnormalities refer to sperm which are able to fertilise an egg but have a high chance of subsequent problems such as embryonic death or early pregnancy loss. Many uncompensable sperm defects are associated with problems in sperm DNA or chromatin.

We encourage all producers to include semen morphology in their BullCheck™ exams.  

Article written by ChenoVet

02 What is laminitis?

Laminitis (also known as founder) is a potentially crippling condition of horses and ponies which can be fatal in severe cases. 

By definition, laminitis is inflammation of the ‘laminae’ of the foot – the sensitive soft tissue structures that attach the pedal bone of the foot to the hoof wall. Inflammation and damage to the sensitive laminae causes extreme pain and can lead to instability of the pedal bone in the hoof. In severe or chronic cases it can lead to irreversible rotation and/or sinking of the pedal bone within the hoof capsule. All four feet can be affected, although the fore-limbs are more frequently and severely affected than the hind-limbs as they support around 60% of the horse’s weight, while the hind-limbs support the other 40%.

What does laminitis look like?

In the initial stages, laminitis may present with signs such as:

  • Reluctance to move about
  • Sore-footedness, especially on hard ground
  • ‘Leaning back’ stance
  • Weight shifting from foot to foot
  • Excessive lying down

Horses or ponies which have suffered chronic (ongoing) laminitis may have signs of abnormal hoof growth such as hoof wall ‘rings’ and long, dished toes. 

It is important to note that laminitis can affect all breeds of horses, not just fat ponies.

What causes laminitis?

Laminitis is a complex condition with a range of potential causes and underlying conditions:
Nutritional causes – e.g. over-feeding
Metabolic conditions – e.g. Equine Metabolic Syndrome, Cushing’s disease
Toxins – e.g. grain poisoning, retained placenta in broodmares
Traumatic causes – e.g. over-trimming, repeated concussion on hard surfaces

Diagnosis & treatment

We will be able to make a diagnosis based on medical history and examination, and with the aid of X-rays. Treatment will vary depending on the underlying cause but is generally aimed at reducing the inflammation in the feet to prevent or limit irreversible structural changes.

03 Your guide to cattle castration
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Do you know your legal obligations and best practices when it comes to castrating cattle? Here are some key points from the Australian Animal Welfare Standards and Guidelines for your information. 

Standards - legal requirements

A person in charge must ensure the use of appropriate pain relief when castrating cattle, unless cattle are:

  1. less than 6 months old; or
  2. less than 12 months old if at their first yarding, and where the later age is approved in the jurisdiction

Guidelines - recommended best practices

  • As young as possible (less than 12 weeks of age) and prior to weaning
  • Calves should be more than 24 hours old when castrated
  • Calves under 2 weeks should be castrated by the rubber-ring method
  • Calves over 2 weeks should be castrated by the cutting method: excision to extend fully to base of scrotum to allow effective drainage and reduce the risk of infection
  • Rubber rings or tension bands should be correctly positioned to ensure tension is achieved to block the arterial blood flow
  • Surgical procedures should be done with pain relief, operators should seek advice on current pain minimisation strategies
04 The dreaded dummy foal

Dummy foal syndrome, also known as Neonatal Maladjustment Syndrome, is a broad term that describes a range of conditions that may cause a newborn foal to exhibit abnormal behaviours and/or neurological signs. Dummy foal syndrome may present at birth, or within 24-48 hours of birth. Dummy foal syndrome affects 3-5% of live born foals. 

What are the signs of a dummy foal?

As the name suggests, these foals act “dumb”. They may show signs such as weakness or collapse, depression or lethargy, lack of interest in nursing and poor suckle reflex, disorientation/circling, abnormal vocalisation or even seizures. 

What causes dummy foal syndrome?

Dummy foal syndrome is thought to result from a lack of oxygen reaching the foal’s brain, either before, during or after birth. Risk factors can include placentitis in the mare, a prolonged or difficult birth (e.g. dystocia, red bag delivery, caesarean), premature birth, and illness or disease.

 

What can be done for dummy foals?

If you suspect your foal may be suffering from dummy foal syndrome please contact us immediately as prompt diagnosis and treatment is critical. We will usually treat a dummy foal with intensive supportive care, including IV fluid therapy +/- plasma transfusion, oxygen therapy, nutritional support, anti-inflammatory medication and antimicrobial treatment.

Foals that respond well to treatment often go on to live long, healthy and successful lives.

05 Managing coccidiosis in stock
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Nearly all vertebrate animals host one or more species of the protozoa Eimeria which is the bug responsible for causing coccidiosis. Given this, coccidiosis is a disease which all livestock producers need to be aware of. It causes problems in cattle, sheep, pigs, goats and chickens just to name a few.  

Coccidia develops in the intestinal tract, and produces oocysts that pass in the dung onto the pasture. The spores then infect grazing stock. Often the subsequent infection causes no ill effects, or at least no visible effects. 95% of the loss which occurs with coccidiosis is ‘sub-clinical’, meaning the only effect is reduced feed conversion efficiency and reduced weight gain. However, with stress and overcrowding, particularly under damp unhygienic conditions, profuse diarrhoea can occur with blood and mucous in it which can be accompanied by significant mortality. It is most commonly seen in young stock just before weaning, in feedlots, or other situations where stock are confined at very high stocking rates. 

Do you have a coccidiosis problem?

Most stock are infected early in life without showing signs of infection. However, coccidiosis is usually suspected in lambs too young for a worm problem, or when stock are scouring but fail to respond to drenching (unless significant worm burdens are also present).  

A quick diagnosis is important to work out a plan

If you suspect coccidiosis is causing a problem in your stock, get in touch. Faecal floatation (pictured left) is a quick way to determine if large numbers of coccidia are passing through into the faeces. If you have lost animals, there are often tell-tale signs (e.g. white spots in the intestines) which can raise the alarm. There are treatment and prevention measures which are best discussed on a case-by-case basis.

06 Good grazing practices for environmental management

For livestock producers out there: this brilliant 22 minute TED Talk by Allan Savory gives a great insight into what well-managed grazing practices can do for the environment.